TABLE 1.
CHARACTERISTICS OF WOMEN SELECTED FOR INCLUSION IN THE STUDY COHORT
| Aspirin use in the year prior diagnosis (dosing intensity by quartiles)A |
||||||
|---|---|---|---|---|---|---|
| Characteristic at diagnosis | Non-user N = 2,056 |
Dosing intensity (1%-37%) N = 186 |
Dosing intensity (38%-79%) N = 184 |
Dosing intensity (80%-97%) N = 185 |
Dosing intensity (98%-100%) N = 185 |
|
| Patient details | ||||||
| Age – Median (IQR) | Years | 67 (58, 73) | 72 (65, 77) | 71 (64, 77) | 73 (65, 76) | 72 (66, 77) |
| Comorbidity – Median (IQR) | Drug classes | 6 (3, 10) | 10 (7, 14) | 11 (8, 15) | 11 (7, 15) | 12 (9, 17) |
| Smoking status – (%) | Never | 1,022 (49.7) | 92 (49.5) | 95 (51.6) | 100 (54.1) | 88 (47.6) |
| Past | 245 (11.9) | 23 (12.4) | 20 (10.9) | 22 (11.9) | 23 (12.4) | |
| Current | 456 (22.2) | 33 (17.7) | 31 (16.8) | 30 (16.2) | 34 (18.4) | |
| Unspecified | 333 (16.2) | 38 (20.4) | 38 (20.7) | 33 (17.8) | 40 (21.6) | |
| Screen detected – (%) | Organized B | 257 (12.5) | 15 (8.1) | 24 (13.0) | 21 (11.4) | 21 (11.4) |
| Opportunistic | 94 (4.6) | 7 (3.8) | 5 (2.7) | 8 (4.3) | 9 (4.9) | |
| Concomitant drugs – (%) C | Estrogen | 107 (5.2) | 6 (3.2) | 8 (4.3) | 9 (4.9) | 8 (4.3) |
| Estrogen/Progesterone | 164 (8.0) | 9 (4.8) | 7 (3.8) | 6 (3.2) | 10 (5.4) | |
| Statins | 307 (14.9) | 68 (36.6) | 93 (50.5) | 92 (50.5) | 112 (60.5) | |
| NSAID | 876 (42.6) | 101 (54.3) | 89 (48.4) | 94 (50.8) | 101 (54.6) | |
| Beta blocker | 315 (15.3) | 62 (33.3) | 68 (37.0) | 69 (37.3) | 85 (45.9) | |
| Anti-diabetic | 79 (3.8) | 17 (9.1) | 28 (15.2) | 23 (12.4) | 32 (17.3) | |
| - Biguanide | 46 (2.2) | 14 (7.5) | 18 (9.8) | 16 (8.6) | 23 (12.4) | |
| Bisphosphonate | 109 (5.3) | 10 (5.4) | 16 (8.7) | 23 (12.4) | 18 (9.7) | |
| Tumor details | ||||||
| Nodal status – (%) D | Negative | 1,020 (49.6) | 86 (46.2) | 99 (53.8) | 112 (60.5) | 107 (57.8) |
| Positive | 1,036 (50.4) | 100 (53.8) | 85 (46.2) | 73 (39.5) | 78 (42.2) | |
| Tumor size – (%) D | T1 | 848 (41.2) | 71 (38.2) | 84 (45.7) | 78 (42.2) | 62 (33.5) |
| T2 | 916 (44.6) | 87 (46.8) | 81 (44.0) | 84 (45.4) | 98 (53.0) | |
| T3 | 130 (6.3) | 9 (4.8) | 12 (6.5) | 12 (6.5) | 13 (7.0) | |
| T4 | 162 (7.9) | 19 (10.2) | 7 (3.8) | 11 (5.9) | 12 (6.5) | |
| Tumor stage – (%) D | I | 624 (30.4) | 51 (27.4) | 66 (35.9) | 60 (32.4) | 48 (25.9) |
| IIa / IIb | 626/490 (30.4/23.8) | 60/46 (32.3/24.7) | 61/36 (33.2/19.6) | 68/35 (36.8/18.9) | 80/31 (43.2/16.8) | |
| IIIa / IIIb-c | 130/186 (9.0/6.3) | 9/20 (4.8/10.8) | 13/8 (7.1/4.3) | 8/14 (4.3/7.6) | 10/16 (5.4/8.6) | |
| Tumor grade – (%) | Low | 207 (10.1) | 18 (9.7) | 18 (9.8) | 27 (14.6) | 17 (9.2) |
| Intermediate | 921 (44.8) | 83 (44.6) | 105 (57.1) | 84 (45.4) | 81 (43.8) | |
| High | 692 (33.7) | 59 (31.7) | 50 (27.2) | 51 (27.6) | 64 (34.6) | |
| Unspecified | 236 (11.5) | 26 (14.0) | 11 (6.0) | 23 (12.4) | 23 (12.4) | |
| Tumor morphology – (%) | Ductal | 1,462 (71.1) | 135 (72.6) | 122 (66.3) | 128 (69.2) | 131 (70.8) |
| Lobular | 270 (13.1) | 29 (15.6) | 26 (14.1) | 24 (13.0) | 21 (11.4) | |
| Other | 324 (16.3) | 22 (11.8) | 36 (19.6) | 33 (17.8) | 33 (17.8) | |
| ER – (%) | +ve/-ve/Unspecified | 1,384/378/294 (67.3/18.4/14.3) | 125/45/16 (67.2/24.2/8.6) | 130/24/30 (70.7/13.0/16.3) | 127/28/30 (68.6/15.1/16.2) | 131/29/25 (70.8/15.7/13.5) |
| PR – (%) | +ve/-ve/Unspecified | 918/497/641 (44.6/24.2/31.2) | 85/57/44 (45.7/30.6/23.7) | 79/38/67 (42.9/20.7/36.4) | 82/41/62 (44.3/22.2/33.5) | 75/51/59 (40.5/27.6/31.9) |
| HER2 – (%) | +ve/-ve/Unspecified | 227/919/910 (11.0/44.7/44.3) | 27/86/73 (14.5/46.2/39.2) | 21/73/80 (12.1/42.0/46.0) | 15/91/79 (8.1/49.2/42.7) | 27/89/69 (14.6/48.1/37.3) |
| Aspirin exposure (year prior to diagnosis) | ||||||
| Number of Rx dispensed | - - | 522 - | 1,587 - | 2,166 - | 2,353 - | |
| Rx doses – (%) | 75mg/300mg/Other | - - | 379/107/36 (72.6/20.5/6.9) | 1,247/264/76 (78.6/16.6/4.8) | 1,914/186/66 (88.4/8.6/3.0) | 2,137/160/56 (90.8/6.8/2.4) |
| Dosing intensity-Median(IQR)A | % | - - | 16.4 (7.7, 26.6) | 57.0 (47.0, 71.6) | 90.4 (86.8, 94.2) | 100.0 (99.2, 100.0) |
| Aspirin exposure (diagnosis to end of follow-up) | ||||||
| Dosing intensity-Median(IQR) E | % | 0.0 (0.0, 0.0) F | 23.6 (0.0, 75.3) | 74.2 (44.5, 90.9) | 89.4 (65.0, 96.2) | 97.2 (88.5, 100.0) |
IQR: Inter-Quartile Range. ER: Estrogen Receptor. PR: Progesterone Receptor. HER2: Human Epidermal Growth Factor Receptor 2. Rx: Prescription. NSAID: Non-Steroidal Anti-Inflammatory Drug.
A
Dosing intensity calculated as the number of days with a supply of aspirin available in year prior to diagnosis, divided by 365.
B
Identified from linked BreastCheck national screening program records.
C
In the year prior to breast cancer diagnosis.
D
AJCC Cancer Staging Manual 6th Edition. Springer, 2002.
E
Post-diagnostic dosing intensity calculated as number of days with supply of aspirin available from diagnosis to end of follow-up, divided by the number of days from diagnosis to end of follow-up.
F
400 women initiated de-novo aspirin use between their breast cancer diagnosis and the end of follow-up.